The original language and your translation on every YouTube™ video — a single, non-overlapping layer that switches cleanly, sentence by sentence. Free and open source.
It reads the video's real caption track, translates it, and renders both languages in one tidy overlay you can style and drag.
它读取视频真实的字幕轨道，翻译后把两种语言渲染在同一层整洁的字幕里，样式可调、位置可拖。
01
Pick your language pair
选择你的语言组合
Choose one of 16 target languages in the popup and which translation engine to use. A live preview shows the result as you tweak.
在弹窗中从 16 种目标语言里选一种，并选择使用哪个翻译引擎。实时预览会随你的调整即时呈现效果。
02
Play any video
播放任意视频
Press play on any YouTube™ video. Captions turn on automatically, and the player-bar button toggles the overlay on or off.
在任意 YouTube™ 视频上点击播放。字幕会自动开启，播放栏上的按钮可随时开关字幕层。
03
Read both lines
同时读两行
The original language sits on one line, your translation on the other — one non-overlapping layer that switches sentence by sentence.
原文占一行，你的译文占另一行——同一层字幕互不重叠，逐句切换。
Single layer · never overlaps单层显示 · 永不重叠
No more subtitle soup
告别字幕一团糊
Other tools stack a second track on top of YouTube's own captions and they collide into a blob. This extension hides YouTube's native layer and renders one clean overlay instead.
Original language, at full strength — exactly as spoken in the video.
原文，完整清晰——与视频里说的一字不差。
Line 2第二行
Your translation, in a dimmer tint underneath, so the two never blur together.
你的译文，以稍淡的色调置于下方，两行绝不会糊在一起。
Hidden已隐藏
YouTube's™ own caption layer is turned off, so the two sources never overlap.
YouTube™ 自带的字幕层已关闭，因此两个来源永不重叠。
Rendered from the timed caption cues, so lines switch by whole sentence — no word-by-word jitter.基于带时间轴的字幕轴点渲染，因此字幕整句切换——不会逐字抖动。
Features功能特性
Everything you'd want from a subtitle layer
一层好字幕该有的，它都有
Two translation engines两套翻译引擎
Translation that's aligned and lag-free
对齐精准、毫无延迟的翻译
Use YouTube's™ own whole-track translation for perfectly aligned, instant captions — with an automatic fallback to Google Translate's free endpoint, prefetched so there's no lag.
使用 YouTube™ 自带的整轨翻译，字幕对齐精准、即时呈现——并会自动回退到 Google 翻译的免费接口，提前预取，毫无延迟。
Primary首选YouTube™ whole-trackYouTube™ 整轨翻译
Perfectly aligned to the video's timing, and instant.
与视频时间轴完美对齐，即时呈现。
Fallback回退Google TranslateGoogle 翻译
Free endpoint, prefetched ahead of playback — no lag.
免费接口，播放前提前预取——毫无延迟。
Fully customizable高度可定制
Style every line exactly how you like
每一行都按你的喜好来
Set per-line font, size, text color, background color and opacity, outline, and line spacing — and choose which line sits on top. A live preview in the popup shows every change instantly.
Per-line font, size, and text color每行独立的字体、字号和文字颜色
Background color and opacity, outline, and line spacing背景颜色与透明度、描边和行间距
Choose which line sits on top, with a live preview选择哪一行在上，带实时预览
16 target languages16 种目标语言
Draggable · one-click toggle可拖动 · 一键开关
Put the subtitles wherever you want
字幕想放哪就放哪
Grab the handle and drop the subtitle box anywhere on the video — it stays put. Double-click to reset, and it works in fullscreen too. A button in the player control bar turns the overlay on and off.
Yes. There are no analytics, no tracking, and no accounts. Caption text is sent only to the translation service you choose — nothing else leaves your browser. The extension is open source under the MIT license, so you can verify this yourself.
私密。没有任何统计分析、追踪或账号。字幕文本只会发送到你自己选择的翻译服务——其余内容都不会离开你的浏览器。本扩展基于 MIT 许可开源，你可以自行核实。
Which browsers does it work on?它支持哪些浏览器？
Chrome, Edge, and other Chromium-based browsers on version 111 or newer. It's a Manifest V3 extension. You can install it from the Chrome Web Store, or load it unpacked from the source on GitHub.
支持 Chrome、Edge 以及其他基于 Chromium、版本 111 或更高的浏览器。它是一个 Manifest V3 扩展。你可以从 Chrome Web Store 安装，也可以从 GitHub 上的源码以未打包方式加载。
Does it cost anything?它收费吗？
No. It's completely free and open source under the MIT license. There's no paid tier, no subscription, and no account to create.
不收费。它完全免费，基于 MIT 许可开源。没有付费档位、没有订阅，也不用创建账号。
Does it work with auto-generated captions?它支持自动生成的字幕吗？
Yes. It reads the video's real caption track, and it can turn captions on for you automatically. If needed, it also falls back to reading the on-screen caption text, and it survives YouTube's single-page navigation.
No. YouTube's™ whole-track translation is instant and perfectly aligned, and the Google Translate fallback is prefetched ahead of playback so there's no lag. Lines are rendered from the timed cues, so they switch by whole sentence without flicker.
